Means for promoting circulation in steam-boilers.



PATBNTED MAR. 26, 1907.

S. J. ROSS. MEANS FOR PROMOTING CIRCULATION IN STEAM BOILERS.

APPLICATION FILEDSEPT. 25, 1905.

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dicing 7 62 30015 UNITED STATES PATENT onrron.

SIDNEY JOHN ROSS, OF LONDON, ENGLAND, ASSIGNOR OF ONE-THIRD TO HARRYSOHOFIELD AND ONE-THIRD TO OLIVER PRESCOTT MAOFAR- LANE, OF LONDON,ENGLAND.

MEANS FOR PROMOTING CIRCULATION IN STEAM-BOILERS...

Specification of Letters Patent.

Patented March 26, 1907.

Application filed September 25, 1905. Serial No. 280,071.

To (all whom it may concern:

Be it known that I, SIDNEY JOHN Ross, a subject of the King of GreatBritain, residing at 37 Lower Clapton road, London, N. E., England,marine engineer, have invented certain new and useful Improvements in orRelating to Means for Promoting Circulation in Steam-Boilers, of whichthe following is a specification.

This invention has reference to means for promoting circulation insteam-boliors, more especially those of the cylindrical or shell t 7 es.

in important feature of the invention is that in the carrying out of thesame the use of special cross-tubes or circulating-tubes is dispensedwith and that there is no need to make holes in the walls of the finesor combustion-chambers.

According to the invention a portion of the water-spaoesay, forinstance, the wet back in what is known as a wet-back marine boiler orany other suitable space, according to the type of boileris utilized asa means for promoting circulation, such water-space being inclosed moreor less at the sides by suitable light sheet-metal orother walls ordivision-plates, so as to form a vertical water-chamber, as it were,which is practically only in free communication with the rest of thewater-space at its upper and lower parts. The arrangement is such thatwhen thewater in the inclosed space or in thewet back becomes heated (asit does, for instance, by the rush of the flames which strike the wallof the wet back as they turn up into the returntubes) it naturally flowsin an upward direction, fresh water entering the bottom of the saidspace to take its place, thus setting up an eflicient and positivecirculation within the boiler.

In order to provide for a longitudinal circulation of the water, the wetback or other circulation-space may be provided with elbows, nozzles,cowls, or the like fitted, for instance, at boththe lower and upper endsthereof. Those cowls at the top may have their mouths directed forwardor so as to throw the water along the tops of the furnace-crowns towardthe front of the boiler, where it will descend and flow back under thefines to the circulating arrangement again, and so on.

i In order that the invention may be readil understood, I will nowproceed to describe I the same by reference to the accompanyingdrawings, in whioh Figure 1 is a longitudinal section showing a wet-backmarine boiler with the improved arrangement applied thereto. Fig. 2 is aseparate side view of the casing for the wetback space providedwithordinary elbows that is to say, elbows of circular section, Fig. 3 beinga front view thereof. Fig. 4 illus- .trates the application of thecirculating means to a dry-back boiler. Fig. 5 is a transverse sectionthrough the wet back on the line 5 5 of Fig. 1, but showing wide flatelbows such as it is preferred to use. Fig. 6 shows a modificationhaving a circulationcasing at both sides of the fire-box.

The same letters of reference indicate corresponding parts throughoutthe drawings.

a is the boiler; 12, the furnace; b, the combustion-chamber, and b theusual. returntubes for the fuel gases. The rear-waterspace or wet backusual in such boilers is indicated at c, Fig. 1, while 0 indicates thecorresponding part in a dry-back boiler, as in Fig. 4: or on theopposite side. of the combustion-chamber in a wet-back boiler, as inFig. 6. To render such a space efiicient for circulation purposes, thereis fitted around it entirely inside the boiler a casing shell or.sheathing 0 to which the lower elbows orhoods d and the upperelbows orhoods e are secured, these consisting either of plain tubular elbows, asin Fig. 3, or wide fiat elbows, asv

in Fig. 5, the latter giving a freer circulation, almost analogous to acascade arrangement. The casing being internal to the boiler need onlybe of thin metal, since its purpose. is merely to prevent freecommunication of the water inside and outside it taking place otherwisethan through these nozzles or hoods d and c. any convenient wayforinstance, by fixing it to the stay-bolts 0?, usual inthis type ofboiler. As it is not subject to any material difference of pressure, itis therefore not necessary that its joints should actually be madetight, so long as they are a sufficiently good fit to preventappreciable leakage or passage of water round its edges. The casing 0thus forms an inclosed water-chamber which is practically equivalent toa wide flat circula- It may be secured in place in tion-tube without,however, requiring any cutting of the boiler-shell or the fire-box wallfor fitting it in position. It will also be seen that the water in thecirculation-space c or c is in contact with the flat back or front wallof the combustion-chamber, and therefore becomes rapidly heated. Theaforesaid hoods d and e are secured by tie-bolts f, which may be readilyhooked round the stay-bolts c or they may be otherwise fixed in anysuitable manner, and instead of a single wide flat elbow, as shown infull lines in Fig. 5, at the top and bottom of the sheathing or casing ca series of plain nozzles, such as in Figs. 2 and 3, may be arrangedsideby side, as indicated by the dotted circles in the said Fig. 5. Theaction of the said circulating means or arrangements will be readilyunderstood. With the adjacent parts of the boiler the internal casing orshell 0 forms in its interior a narrow inclosed water-space open only atthe top and bottom through the nozzles. I-Ience as the flames from thefurnace b strike the wall 6 of the space a (forming the wet back of thecombustion-chamber b) the water therein becoming highly heated naturallybegins to ascend in the said wet-back space and flows out therefrom atthe top hoods or nozzles 6. Fresh water from the comparatively coldbottom of the boiler at the same time enters the lower nozzles d. ,Inthis way an active circulation throughout the boiler is set up, as shownby the arrows, Fig. 1.

In the arrangement shown in Fig. 4 the same action takes place, theflames and gases in this instance striking the tube-plate behind thespace c as they rush from the fur nace b into the tubes b In this waythe water in the said space is heated in the manner described, and acirculation is set up practically in the same way, as in Fig. 1.

The arrangement shown in Fig. 6 combines the features shown in Figs. 1and 4 in a single arrangement for a wet-back boiler, the spaces a and cacting as in the previous examples. The wall of the front space 0 is,however, continued directly downward, as shown, and provided with shortinlet-nozzles or elbows d at its lower end. The rear space, on the contrary, has its inlet-nozzles connected with long tubes d extendingforward through the bottom part 0 of the space 0 and passing toward thefront of the boiler, in order to draw in water in advance of the nozzlesd, and thus distribute the circulation effect more uniformly. Obviouslya similar internal shell or casing, such as 0 may be fitted round theflues or furnaces of Lancashire and like boilers to promote circulationin the same way. In such a case the said shell would be of practicallycylindrical shape to correspond to that of the fines.

What I claim, and desire to secure by Letters Patent of the UnitedStates, is

1. A wet-back marine boiler having its wet-back space inclosed at thesides, and provided at top with means for discharging water therefrom ina forward direction, so as to set up longitudinal circulation in theboiler, substantially as described.

2. A wet-back marine boiler, having its wet-back space inclosed at thesides and provided at the top and bottom with forwardlydirected outletand inlet means, for the purpose of setting up longitudinal circulationin the boiler, substantially as described.

3. In a wet-back marine boiler, the combination of means for inclosingthe space he hind the combustion-chamber, and means opening below thewater-level for discharging the water from the inclosed space in aforward direction, substantially as described.

4. In awetback marine boiler, the combination of means for inclosing thespace behind the combustionchamber, an outlet from said space openingbelow the waterlevel and discharging water in a forward direction, andan inlet at the bottom of said space to admit the water in a backwarddirection, for the purpose of setting up a longitudinal circulation inthe boiler, substantially as described.

5. In a steam-boiler, the combination of a combustion chamber aninclosed waterspace at one end of said chamber, and a correspondinginclosed water-space in front of said chamber, said spaces being incommunication at top and bottom with the main water-space of the boiler,substantially as described.

6. In a steam boiler the combination of a combustion-chamber, aninclosed water-space at one end of said chamber, a correspondinginclosed water-space in front of said chamber, nozzles for directing thewater ascending from spaces in a forward direction and means foradmitting water to the lower part of either of said chambers from apoint near the front of the boiler, substantially as described. I

In testimony whereof I have hereunto set my hand, in presence of twosubscribing witnesses, this 24th day of August, 1905.

SIDNEY JOHN ROSS.

Witnesses:

C. BARNARD BURDON, ALFRED NUTTING.

